[A Case of Autoimmune Acquired Factor XIII Deficiency Diagnosed from Recurrent Postoperative Bleeding].

The patient was a 79-year-old man with ureteroileal anastomotic stricture after a Bricker ileal conduit. Endourological treatment of stenosis was performed via percutaneous nephrostomy and ileal conduit. The patient experienced lower abdominal pain on the following day, and computed tomographic (CT) scan showed hematoma retention around the kidney and active bleeding from the renal artery branches. Transarterial embolisation (TAE) was performed and the bleeding was controlled. Two days later, there was a sudden progression of anemia and CT showed an increase in hematoma around the kidney. We subsequently performed nephrectomy for hemostasis. Five days later, the anemia progressed further. There was hematoma retention in the retroperitoneal cavity, and emergency laparotomy hemostasis was performed. Routine coagulation test results were normal. Heavy bleeding was observed several days after TAE and the possibility of coagulation factor XIII deficiency was considered. Factor XIII deficiency was confirmed by a low factor XIII activity level. The patient was given plasma-derived factor XIII. After receiving factor XIII replacement, factor XIII activity remained unchanged and the patient continued to bleed. Thereafter, a cross-mixing test was performed and the patient was diagnosed with autoimmune acquired factor XIII deficiency. Cortical steroids were administered to remove the factor XIII inhibitor. Steroid administration showed a rapid increase in factor XIII activity, and bleeding symptoms were no longer observed. In cases of serious bleeding of unknown cause with a normal coagulation profile, acquired factor XIII deficiency should be suspected and factor XIII activity measured.

[Incidence of Antiresorptive Agent-Related Osteonecrosis of the Jaw in Urologic Cancers].

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a serious adverse event of bone resorption inhibitors (BRIs), such as zoledronic acid and denosumab. Based on the results of phase 3 clinical trials for BRIs, the frequency of ARONJ is 1 to 2%, but the actual frequency is presumed to be higher. We studied 143 patients with urologic cancers with bone metastases who were treated with zoledronic acid or denosumab at our hospital between April 2007 and March 2020. ARONJ occurred in 24 patients (16.8%) ; that is, 14 of the 113 patients (12.4%) who received zoledronic acid alone, 8 of the 24 patients (33.3%) who received denosumab alone, and 2 of the 6 patients (33.3%) who sequentially switched from zoledronic acid to denosumab. ARONJ was cured in 8 patients (33.3%), improved in 3 patients (12.5%), unchanged in 4 patients (16.7%), and worsened in 9 patients (37.5%). The frequency of ARONJ increased as the duration of BRI administration prolonged. Time-to-ARONJ was shorter in patients treated with denosumab than in patients treated with zoledronic acid. The occurrence of ARONJ may be underestimated; therefore, further studies are needed to investigate the actual frequency of ARONJ in Japan.